Armored glazing manufactured from mass-produced laminated glazing constituents

ABSTRACT

A process for manufacturing a light armored curved laminated glazing intended to be fitted in an opening of a transport vehicle suitable for the mass-production fitting of a curved laminated glazing containing two glass sheets, wherein use is made of at least three constituent curved glass sheets of such mass-produced curved laminated glazing containing two glass sheets, including both sheets from one and the same such mass-produced curved laminated glazing containing two glass sheets, which have been previously bent together.

The invention relates to the manufacture of light armored laminatedglazings, intended to protect against perforation by .22 Long Riflebullets, or penetration using a baton or the like. Advantageously, theselight armored glazings can be fitted to the body opening of a transportvehicle without modifying anything, i.e. can be fitted to amass-produced body.

Currently, these glazings are manufactured in dedicated facilities, inamounts incomparably smaller than those of mass production. The glasssheets forming such a glazing are bent together, i.e. especially ingroups of four to eight glass sheets, by gravity. One-pot furnaces orbatch furnaces are used. The glass sheets are at a static station, it isthe tools that come to them. The manufacturing times are relativelylong, since obtaining the required optical quality and geometricaccuracy requires extensive adjustments. Before obtaining the requiredstability of properties of the glazings, many articles must be scrapped.

The invention was therefore motivated by the concern for producing lightarmored glazings for transport vehicles such as mass-produced motorvehicles, without modification of their body. The invention also targetsshorter manufacturing times, an improvement in the optical quality ofthe glazings produced and in their geometric compatibility with theframe in which they are intended to be installed.

For this purpose, one subject of the invention is a process formanufacturing a light armored curved laminated glazing intended to befitted in an opening of a transport vehicle suitable for themass-production fitting of a curved laminated glazing containing twoglass sheets, characterized in that use is made of at least threeconstituent curved glass sheets of such mass-produced curved laminatedglazing containing two glass sheets, including both sheets from one andthe same such mass-produced curved laminated glazing containing twoglass sheets, which have been previously bent together. As will be seenin greater detail subsequently, the two glass sheets of a mass-producedcurved laminated glazing often differ from one another due to theircomposition (one may be tinted, and the other clear), the layers orscreen-printed patterns that they bear and their thickness, thusreference will be made subsequently, according to common usage, to theinner glass sheet which is the one intended to be oriented toward thepassenger compartment of the vehicle, and to the outer sheet which isthe one intended to be oriented toward the external atmosphere. The twosheets of mineral glass of a mass-produced curved laminated glazing arebent together by gravity so that the curvature over their entire surfaceis exactly identical, even if the inner sheet and outer sheet have aslightly different geometry from one another so that they are notinterchangeable.

The invention makes it possible to obtain the desired protection againsta .22 Long Rifle shot or the like, against attacks and penetrations, andalso a required optical and geometric quality of the laminated glazing,which are improved relative to those obtained in the current small-scaleproductions. The number of glass sheets scrapped is itself also muchlower.

Mass-produced curved laminated glazings containing two glass sheets,such as motor vehicle windshields, have the most constant geometrypossible of their periphery, guaranteeing a perfect adaptation to thebody opening into which they are installed, both as regards the contourof their periphery and the angle formed by their edge surface. Thus, anexcellent coupling accuracy is obtained. Furthermore, according to theprocess of the invention, the glazing obtained may be fitted in the bodyopening, in particular via the outside, and/or the inner face of theglazing may bear against the frame of the opening, in the same way as amass-produced laminated windshield containing two glass sheets.

This intrinsic maximum reproducibility of mass production is also aguarantee of an optimal optical quality of the laminated glazing, and ofa considerable cost reduction making, within the context of theinvention, a light armored glazing available to the greatest number ofpeople.

In accordance with preferred features of the process of the invention:

-   -   use is made of at least four constituent glass sheets of said        mass-produced laminated glazing containing two glass sheets;    -   use is made of at most six constituent glass sheets of said        mass-produced laminated glazing containing two glass sheets.

In a first main variant of the process of the invention, joined to thetwo glass sheets forming said one and the same mass-produced curvedlaminated glazing, on the side of the outer sheet thereof, is at leastone outer glass sheet intended for another mass-produced curvedlaminated glazing containing two glass sheets, and/or on the side of itsinner sheet, is at least one inner glass sheet intended for anothermass-produced curved laminated glazing containing two glass sheets. Theexpression “intended for” refers here and subsequently to the fact thatthe glass sheet was bent by gravity with its “twin” glass sheet so as tomatch the curvature thereof as closely as possible over its entiresurface, as mentioned above.

A light armored laminated glazing according to this first main variantwill therefore be manufactured by joining to the inner glass sheet andthe outer glass sheet of a first mass-produced curved laminate:

-   -   on the side of this inner glass sheet, the inner glass sheet of        one or more other mass-produced curved laminate(s), and/or    -   on the side of this outer glass sheet, the outer glass sheet of        one or more other mass-produced curved laminate(s).

When use is made simultaneously of at least one inner glass sheet of onesaid other mass-produced curved laminate and at least one outer glasssheet of one said other mass-produced curved laminate, it is notexcluded for these to be intended for one and the same othermass-produced laminate (and for them to have, in particular, been benttogether).

In a second main variant of the process of the invention, joined to thetwo glass sheets forming said one and the same mass-produced curvedlaminated glazing, on one side or the other thereof, are the two glasssheets, in adjacent position, of at least one other mass-produced curvedlaminated glazing containing two glass sheets. The two glass sheets ofthe at least two mass-produced curved laminated glazings are in adjacentposition; having been bent together in pairs by gravity, their surfaceshave exactly the same curvature. As regards the curvature, which maydiffer very slightly from one mass-produced curved laminate containingtwo glass sheets to the next, this difference in no way preventslamination with any conventional interlayer adhesive of polyvinylbutyral, ethylene-vinyl acetate or ionomer resin type. The glass sheetsmay be joined in a state already laminated by two sheets of one at leastof the mass-produced curved laminates, which is then optionally heatedin order to be joined to the other glass sheets, or before laminatingall these mass-produced curved laminates containing two glass sheets.

These first and second main variants of the process of the invention maybe carried out simultaneously.

Another subject of the invention is a light armored laminated glazingmanufactured according to the process described above, in which theglass sheets which form it have a thickness of between 1 and 4 mm,preferably at least equal to 1.3 mm and at most equal to 3.2 mm.

The glass sheets of this glazing are bonded to one another by aninterlayer adhesive. This may be polyvinyl butyral (PVB) in thicknessesof 0.76 mm or half this thickness or combinations of multiples of thesethicknesses depending on the ballistic requirements and/or depending onthe requirements for good lamination, stretched to a thicknessapproximately of 0.6 mm, ethylene-vinyl acetate (EVA), or a resin suchas ionomer resin, without this list being limiting. The interlayeradhesive may provide an increased penetration and/or ballisticresistance, and also other functionalities such as acoustic insulation.

According to a first preferred variant of the light armored glazing ofthe invention, its face opposite the one where an impact is likely tooccur is shatterproof due to the fact that it consists of apolycarbonate sheet having a thickness of between 1.8 and 4, preferably2.2 and 3.3 mm, which is bonded to a glass sheet by a layer ofpolyurethane.

According to a second preferred variant of the light armored glazing ofthe invention, its face intended to be oriented toward the inside of thepassenger compartment is shatterproof due to the fact that it consistsof a polyethylene terephthalate sheet provided with a polysiloxane-typescratch-resistant and/or functional coating (for exampleanti-condensation or anti-fogging coating rendered thus byfunctionalization of the polysiloxane by hydrophilic functions) andbonded to a glass sheet by a layer of polyurethane or polyvinyl butyral.

Another subject of the invention consists of the application of a curvedlaminated glazing described above as a motor vehicle windshield, inparticular as a light police vehicle or truck windshield. This curvedlaminated glazing is bulletproof and resistant to penetration by abaseball bat or equivalent, while remaining light.

The invention will now be better understood in light of the followingexemplary embodiments.

EXAMPLE 1

A light armored windshield is manufactured from clear soda-lime floatglass sheets bent in pairs with a view to forming mass-producedlaminated windshields containing two glass sheets. The inner glasssheets have a thickness of 1.6 mm, the outer glass sheets have athickness of 2.1 mm.

The inner face of the inner glass sheets, referred to as face 4 in thelaminates containing two glass sheets, face 1 being the one in contactwith the external atmosphere, bears a screenprinting annealed in thebending furnace.

Assembled, from the inside toward the outside of the laminate, are theinner glass sheet and the outer glass sheet that are intended for afirst mass-produced windshield containing two glass sheets, the outerglass sheet intended for a second mass-produced windshield containingtwo glass sheets, then the outer glass sheet intended for a thirdmass-produced windshield containing two glass sheets. The glass sheetsare bonded in pairs by a sheet of stretched polyvinyl butyral having athickness of 0.6 mm.

According to a first variant, a 2.5 mm sheet of polycarbonate (PC) isbonded to the inner face of said inner glass sheet by means of a 1.9 mmthick layer of polyurethane.

According to a second variant, a complex consisting of a 0.38 mm,respectively 0.76 mm, sheet of plasticized PVB and of a 0.18 mm sheet ofpolyethylene terephthalate (PET) coated with a layer of polysiloxane,sold by the company DUPONT DE NEMOURS under the registered trademarkSpallshield® SG2—157, respectively—307, is bonded to the inner face ofsaid inner glass sheet.

EXAMPLE 2

A light armored windshield is manufactured from soda-lime float glasssheets bent in pairs with a view to forming mass-produced laminatedwindshields containing two glass sheets. The inner glass sheets have athickness of 1.4 mm, the outer glass sheets have a thickness of 1.6 mm.

The inner glass sheets are clear, the outer glass sheets are tinted andtheir inner face, referred to as face 2 in the laminates containing twoglass sheets, bears a screenprinting that has in particular the functionof hiding an underlying electrical connection and/or the peripheralablation or demargination of thin layers on the outer face of the innerglass sheets, for example.

Assembled in this example, this time from the outside toward the insideof the laminate, are the outer glass sheet and the inner glass sheetthat are intended for a first mass-produced windshield containing twoglass sheets, then successively the inner glass sheet intended for asecond, a third, a fourth then a fifth mass-produced windshieldcontaining two glass sheets.

The same adhesive interlayer is used between two glass sheets as in thepreceding example, and the same shatterproof partial laminate consistingof the polyurethane layer and of the polycarbonate sheet is assembled onthe inner face of the partial laminate consisting of all the glasssheets bonded to one another.

It is possible to use acoustic PVB in order to bond certain glass sheetstogether, or all the glass sheets, or else to replace one or more PVBlayer(s) with a high mechanical performance resin, in particular anionomer resin sold by the company DuPont de Nemours under the registeredtrademark SentryGlas® Plus, in a thickness of 0.89, 1.52 or 2.28 mm inparticular. The relative thinness of the glass sheets of the curvedlaminated glazing of the invention is particularly well suited to theuse of this ionomer resin, the cooling of which is thus accelerated withrespect to that which occurs with thicker glass sheets.

It is also possible to use several pairs of thicknesses of outer sheets,respectively inner sheets, of mass-produced laminates containing twoglass sheets, inter alia:

-   -   2.1, respectively 2.1 mm;    -   2.6, respectively 2.1 mm, in particular.

EXAMPLE 3

Example 1 is reproduced, apart from the difference that the glassportion consists exclusively of two mass-produced curved laminatedglazings containing two glass sheets, which are heated before beinglaminated together, and that all the interlayer adhesives consist of a0.89 mm layer of an ionomer resin sold by the company DuPont de Nemoursunder the registered trademark SentryGlas® Plus.

The glazings from examples 1 to 3 have a desired functionality ofballistic protection and protection with respect to penetration. Withrespect to small-scale productions, shorter manufacturing times, animprovement in the optical quality of the glazing, in the stability, theaccuracy of its geometry, and therefore in its adaptation to the bodyopening into which it is intended to be installed, are obtained.

1. A process for manufacturing a light armored curved laminated glazingintended to be fitted in an opening of a transport vehicle suitable fora mass-production fitting of a curved laminated glazing containing twoglass sheets, the process comprising assembling together at least threeconstituent curved glass sheets of such mass-produced curved laminatedglazing containing two glass sheets to form said light armored curvedlaminated glazing, said at least three curved glass sheets includingboth sheets from one and a same such mass-produced curved laminatedglazing containing two glass sheets, which have been previously benttogether.
 2. The process as claimed in claim 1, wherein the assemblingtogether of at least three constituent glass sheets includes assemblingtogether at least four constituent glass sheets of said mass-producedcurved laminated glazing containing two glass sheets, wherein the atleast four constituent glass sheets include two pairs of glass sheetsand wherein the glass sheets in each of the two pairs have beenpreviously bent together.
 3. The process as claimed in claim 1, whereinthe assembling together of at least three constituent glass sheetsincludes assembling together at most six constituent glass sheets ofsaid mass-produced curved laminated glazing containing two glass sheets,wherein the at most six constituent glass sheets include three pairs ofglass sheets and wherein the glass sheets in each of the three pairshave been previously bent together.
 4. The process as claimed in claim1, wherein the assembling comprises joining to the two glass sheetsforming said one and the same mass-produced curved laminated glazing, ona side of an outer sheet thereof, at least one outer glass sheetintended for another mass-produced curved laminated glazing containingtwo glass sheets, and/or on a side of an inner sheet, is at least oneinner glass sheet intended for another mass-produced curved laminatedglazing containing two glass sheets.
 5. The process as claimed in claim1, wherein the assembling comprises joining to the two glass sheetsforming said one and the same mass-produced curved laminated glazing, onone side or the other thereof, two glass sheets, in adjacent position,intended for at least one other mass-produced curved laminated glazingcontaining two glass sheets.
 6. A light armored curved laminated glazingmanufactured as claimed in claim 1, wherein the glass sheets which formthe light armored curved laminated glazing each have a thickness ofbetween 1 and 4 mm.
 7. The curved laminated glazing as claimed in claim6, wherein the glass sheets which form the light armored curvedlaminated glazing each have a thickness at least equal to 1.3 mm.
 8. Thecurved laminated glazing as claimed in claim 6, wherein the glass sheetswhich form the light armored curved laminated glazing each have athickness at most equal to 3.2 mm.
 9. The curved laminated glazing asclaimed in claim 6, wherein the glass sheets which form the lightarmored curved laminated glazing are bonded to one another by aninterlayer adhesive.
 10. The curved laminated glazing as claimed inclaim 9, wherein at least one interlayer adhesive comprises an ionomerresin.
 11. The curved laminated glazing as claimed in claim 6, wherein aface of the curved laminated glazing intended to be oriented toward aninside of a passenger compartment consists of a polycarbonate sheethaving a thickness of between 1.8 and 4 mm, which is bonded to a glasssheet by a layer of polyurethane.
 12. The curved laminated glazing asclaimed in claim 6, wherein a face of the curved laminated glazingintended to be oriented toward an inside of a passenger compartmentconsists of a polyethylene terephthalate sheet provided with ascratch-resistant and/or functional coating and bonded to a glass sheetby a layer of polyurethane or polyvinyl butyral.
 13. A method comprisingmanufacturing a motor vehicle windshield with a curved laminated glazingas claimed in claim
 1. 14. The method as claimed in claim 13, whereinthe motor vehicle windshield is a light police vehicle or truckwindshield.
 15. The curved laminated glazing as claimed in claim 11,wherein the thickness is between 2.2 and 3.3 mm.
 16. A process formanufacturing a light armored curved laminated glazing to be fitted inan opening of a transport vehicle, the method comprising: selecting afirst pair of curved glass sheets from a group of mass-produced pairs ofcurved glass sheets for manufacturing curved laminated glazings thateach contain two glass sheets; selecting at least one curved glass sheetfrom a second pair of curved glass sheets from the group ofmass-produced pairs of curved glass sheets for manufacturing curvedlaminated glazings that each contain two glass sheets, wherein thecurved glass sheets in the first pair of curved glass sheets have beenpreviously bent together, and wherein the curved glass sheets in thesecond pair of curved glass sheets have been previously bent togetherand separately from the curved glass sheets of the first pair of curvedglass sheets, and assembling together the first pair of curved glasssheets with the at least one curved glass sheet of the second pair ofcurved glass sheets.
 17. The process as claimed in claim 16, wherein theassembling comprises assembling together the first pair of curved glasssheets with both curved glass sheets of the second pair of curved glasssheets.
 18. The process as claimed in claim 16, wherein the selectingcomprises selecting at least one curved glass sheet from a third pair ofcurved glass sheets from the group of mass-produced pairs of curvedglass sheets for manufacturing curved laminated glazings that eachcontain two glass sheets, wherein the curved glass sheets in the thirdpair of curved glass sheets have been previously bent together andseparately from the curved glass sheets of the first pair of curvedglass sheets and separately from the curved glass sheets of the secondpair of curved glass sheets and wherein the assembling comprisesassembling together the first pair of curved glass sheets with bothcurved glass sheets of the second pair of curved glass sheets and withthe at least one curved glass sheet of the third pair of curved glasssheets.
 19. The process as claimed in claim 17, wherein the assemblingcomprises assembling together the first pair of curved glass sheets withboth curved glass sheets of the second pair of curved glass sheets andwith both curved glass sheets of the third pair of curved glass sheets.